Exploring TiO 2 -photocatalysts for sunlight conversion has high demand in artificial photosynthesis. In this work, edge-enriched ultrathin molybdenum disulfide (MoS 2 ) flakes are uniformly embedded into the bulk of yolk-shell TiO 2 as a cocatalyst to accelerate photogeneratedelectron transfer from the bulk to the surface of TiO 2 . The as-formed MoS 2 /TiO 2 (0.14 wt%) hybrids exhibit a high hydrogen evolution rate (HER) of 2443 μmol g −1 h −1 , about 1000% and 470% of that of pristine TiO 2 (247 μmol g −1 h −1 ) and bulk MoS 2 decorated TiO 2 (513 μmol g −1 h −1 ). Such a greatly enhanced HER is attributed to the exposed catalytic edges of the ultrathin MoS 2 flakes with a robust chemical linkage (TiS bond), providing rapid charge transfer channels between TiO 2 and MoS 2 . The catalytic stability is promoted by the antiaggregation of the highly dispersed MoS 2 flakes in the bulk of yolk-shell TiO 2 . The exponential fitted decay kinetics of time-resolved photoluminescence (ns-PL) spectra illustrates that embedding ultrathin MoS 2 flakes in TiO 2 effectively decreases the average lifetime of PL in the MoS 2 /TiO 2 hybrids (τ ave = 4.55 ns), faster than that of pristine TiO 2 (≈7.17 ns) and the bulk MoS 2 /TiO 2 (≈6.13 ns), allowing a superior charge separation and charge trapping process for reducing water.

No abstract

No abstract

Two new anthracene derivatives were synthesized as emitter for low power triplet-triplet annihilation upconversion. Compared with anthracene, the emitter exhibits high quantum yields up to 85%. Pd (II) tetraphenylporphyrin which was selected as the sensitizer with the existence of BBA in DMF, We find a pretty high efficiency (Φuc=21.9%) of the upconversion fluorescence at 532nm with a low excitation power density of 0.5w/cm2.With the comparison of Anthracene, BBA and BTPA systems, quantum yield of the emitter is very important to the improving of the efficiency of upconversion.